Is it too early to speculate about the meaning of McCain’s victory?

Probably, especially since we don’t know the final margin of victory or how well Romney did among registered Republicans. But let’s assume that the final margin isn’t very different from the current margin of 8 percentage points. In that scenario, McCain would likely have outpolled Romney among Republican voters as well as independents.
This result would certainly put Romney on the ropes. The focus would then shift to Michigan. If Romney were to win there, the Republicans would have three winners in the first three major races. Huckabee, McCain, and Romney would all be viable. Fred Thompson and Rudy Giuliani would probably have to win in South Carolina and Florida, respectively, to remain viable (a Thompson victory in South Carolina would undermine Huckabee’s viability). The race, in any case, would be wide open.
But now let’s suppose that McCain wins in Michigan. He would then become the front-runner. Huckabee, assuming he wins in South Carolina, would be the main competition. Giuliani or Romney might be able to hang in there as a third choice, but the race would probably be McCain’s to lose.
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